<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>js的垃圾回收机制</title>
</head>
<body>
    <script>
      let num=10
      function fn(){
        const str='andy'
        console.log(str)
      }
      fn()
      console.log(str)
    </script>
</body>
</html>